I agree, realistic sounds – it’s a important part of atmosphere of the game. Sound of the trains (especially heavy locomotives and trains) – it is something indescribable and I hope what in TF will be really cool sounds ;D
And just two videos:
1. http://youtu.be/i8lVibY8bjk – soviet heavy loco (2:15), roars like a Boeing. 😀
2. http://youtu.be/MHbv3zvtTu8 – ukranian train, good sounds of the passanger cars.